Posteriors of the hyperparameters related to the variation in α in redshift are shown. The dark blue dashed lines in the one-dimensional distributions represent the priors. The hyperparameters shown here are the (ascending) power-law index α_z of the modeled merger rate, and then hyperparameters connected to varying α from Eq. (2). This includes α_low, α_high, the width of the sigmoid log(Δz_α) and the middle of the sigmoid ${\overline{z}}_{\alpha }$. We also plot the difference between the high-redshift and low-redshift value Δα, which now is a Gaussian, because the difference of two Gaussians is once again a Gaussian distribution variable.